Effect of CPAP on 6-Minute Walk Test Outcomes in Patients With ECAC

This study is testing whether CPAP (continuous positive airway pressure) — a device that delivers pressurized air to keep airways open — can improve exercise tolerance in patients with excessive central airway collapse (ECAC), a condition where the large airways in the chest collapse during breathing, causing shortness of breath, reduced exercise capacity, and frequent lung infections. ECAC is often underdiagnosed, and many patients also have other breathing problems. Standard treatment involves bronchoscopy (airway inspection) or sometimes airway stenting, but CPAP may offer a non-invasive way to keep airways open during exercise, improving the 6-minute walk test — a standard measure of exercise capacity. You may be eligible if: - You are over 18 years old - You have been diagnosed with ECAC by bronchoscopy or CT scan - You have never used a CPAP device before - You are scheduled for bronchoscopy as part of your standard care - You have a baseline 6-minute walk test result available You may NOT be eligible if: - You have poorly controlled asthma, COPD, obstructive sleep apnea, GERD, or relapsing polychondritis - You have a significant heart arrhythmia or resting heart rate below 50 beats per minute - You cannot walk more than 140 meters in 6 minutes - You cannot tolerate bronchoscopy under sedation or anesthesia - You have a known allergy to bronchoscopy medications Talk to your doctor to see if this trial is right for you.